Method for machining multi-dimensional inclined hole of valve body
Technical Field
The invention relates to an electric spark machining method for a valve body of a hydraulic system, in particular to a method for machining a multi-dimensional inclined hole of the valve body.
Background
The valve body is used as a common part in a hydraulic system, and due to the structural and functional requirements, the valve body is internally provided with a plurality of long and thin oil passages, most of the oil passages have the length-to-fineness ratio of more than 5 and smaller diameters, and holes cannot be machined by a milling method and can only be machined by an electric spark method.
There are currently three solutions for the electrical discharge machining of inclined holes: changing the direction of the electrode chuck by using a tool; changing the direction of the part by using a device; and manufacturing an electrode, and ensuring the processing of the inclined hole by the angle of the electrode. For the multi-dimensional inclined hole, a five-axis electric spark machine tool or a multi-angle steering tool is generally adopted for machining.
CN111889828A discloses a multi-station multi-angle electric discharge machining device, which can realize the machining of multi-dimensional inclined holes, but is too dependent on equipment, and the angle adjustment is inconvenient.
CN210160546U discloses a fixture for electric discharge machining with an angle convenient to adjust, and CN211564771U discloses a device for machining inclined holes for electric discharge equipment, wherein the fixture for electric discharge machining solves the problem that the angle is inconvenient to adjust in the machining process, but can only deflect in one direction and cannot deflect in multiple dimensions.
CN207464379U discloses a multi-angle electrode anchor clamps for spark-erosion machining, CN205200740U discloses a multi-angle discharge machining tool, above-mentioned anchor clamps change the part direction through the device and realize spark-erosion machining, can only be on one-dimensional aspect to the change of angle direction.
CN101774051A discloses an oblique aperture electric spark machining device, the device utilizes the scale on the connector, adjustment electrode angle to realize multidimension degree electric spark machining according to oblique aperture and X axle or Z axle contained angle, but the whole calculation process is loaded down with trivial details, maneuverability is relatively poor, and it is great to receive electrode influence error moreover.
CN207508465U discloses a special main shaft deflection device for electric discharge machining, and CN106001818A discloses a universal angle head suitable for an electric discharge machine tool, the device is connected with a main shaft to realize electrode deflection, the function of the device is similar to the effect of machining a complex electrode by ensuring the angle direction of an inclined hole through an electrode, and the method can realize the inclined hole machining only by programming the machine tool to ensure that the main shaft moves along the direction of the electrode.
CN110064804A discloses a method for machining a spatial angle small hole of an aviation part, which utilizes a five-axis high-speed electric spark machine tool and adopts a coordinate projection method to perform coordinate conversion of the size of the spatial angle small hole, so as to realize the machining of the spatial small hole.
The document entitled "a method for machining a multi-angle inclined plane type hole by reverse evidence seeking" machines a multi-angle inclined plane electrode according to the characteristics of the multi-angle inclined plane type hole of the metering valve, thereby realizing the machining of the multi-angle inclined plane type hole.
In conclusion, the method for changing the direction of the electrode chuck by using the tool and the method for realizing multi-angle electric spark machining by means of the electrode both need to set programs, ensure that the moving direction of the main shaft is consistent with the direction of the electrode, and have the disadvantages of complex overall process, high manufacturing cost and low efficiency; however, the device for changing the direction of the part by using the tool can only realize one-way deflection and cannot realize two-dimensional deflection, and the electrode alignment method is not described in most of the documents.
Disclosure of Invention
The invention provides a method for processing a multi-dimensional inclined hole of a valve body, aiming at solving the problems that the multi-dimensional inclined hole of the valve body cannot be directly processed by a three-axis electric spark machine tool, the processing efficiency is low, and the large-batch processing is not facilitated.
The purpose of the invention is realized by the following technical scheme:
the utility model provides a processing method of valve body multidimension degree inclined hole, adopts three-axis spark-erosion machine tool processing, realizes valve body multidimension degree inclined hole with the help of the frock base and deflects, through the processing that final inclined hole size and angle were realized to size conversion alignment aperture center, wherein:
the tool base is designed according to the following principle:
s1, the upper and lower surfaces, the left and right surfaces, and the front and back surfaces of the base are parallel and corresponding to the valve body;
s2, designing two parallel surfaces on the basis of the left and right side surfaces of the base, wherein the included angle between the parallel surfaces and the side surfaces is equal to the included angle alpha between the surface formed by the central axis of the multi-dimensional inclined hole and the normal of the surface passing through the center of the circle and the side surface of the valve body;
s3, designing an inclined plane on the lower surface of the base, wherein the included angle between the inclined plane and the lower surface of the base is equal to the complementary angle pi/2-beta of the included angle beta between the central axis of the multi-dimensional inclined hole and the lower surface of the valve body;
s4, arranging installation grooves convenient for installing the valve body on the base, wherein each surface of the installation grooves is parallel to and corresponds to each surface of the valve body in shape;
s5, arranging a connecting threaded hole convenient for installing and fixing the valve body on the base, and selecting two mutually vertical surfaces in the valve body to be in contact positioning with the base by considering the positioning of the valve body when the valve body is designed to be fixed with the base;
s6, clamping two parallel surfaces of the base by the vice, wherein the two parallel surfaces are parallel to a xoz surface in a coordinate system of the workbench, and the inclined bottom surface of the base is parallel to a xoy coordinate system of the workbench;
the alignment of the center of the small hole through size conversion comprises the following steps:
s1, determining the position size of the center of the deflected small hole by the positioning size of the center of the original inclined hole, and referring to the coordinate system in FIG. 1, setting the positioning size in the y direction as y0X is the positioning size in the x direction0;
S2, after the valve body is clamped, aligning the electrode in the y direction according to the size y':
y'=y0*cosα+d/2 (1);
wherein y' is the alignment size in the y direction; y is0The original positioning size in the y direction; d is the electrode diameter; alpha is an included angle between a surface formed by the central axis of the multi-dimensional inclined hole and a normal line of the surface passing through the center of the circle and the side surface of the valve body;
s3, after the valve body is clamped, aligning the electrode in the x direction according to the size x':
wherein x' is the alignment size in the x direction; x is the number of0The original positioning size in the x direction; d is the electrode diameter; beta is an included angle between the central axis of the multidimensional inclined hole and the lower surface of the valve body;
and S4, after the alignment is finished, the electrode is downwards processed to a preset depth, and then the processing of the multi-dimensional inclined hole can be finished.
Compared with the prior art, the invention has the following advantages:
the two-dimensional inclined hole machining tool has the advantages of simple structure, convenience in manufacturing, low requirement on equipment (a common three-axis electric spark machine tool), accurate and quick electrode alignment, is particularly suitable for mass part production, and has the effects of reducing the production cost and improving the production efficiency.
Drawings
FIG. 1 is an assembly drawing of a multi-dimensional inclined hole electro-discharge machining tool;
FIG. 2 is a front view of the valve body;
FIG. 3 is a cross-sectional view of the valve body taken through the orifice;
FIG. 4 is a rear view of the valve body;
FIG. 5 is a front view of the base;
FIG. 6 is a top view of the base;
fig. 7 is a perspective view of the base.
Detailed Description
The technical solution of the present invention is further described below with reference to the accompanying drawings, but not limited thereto, and any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be covered by the protection scope of the present invention.
The invention provides a multi-dimensional inclined hole electric spark machining tool, as shown in figures 1-7, the tool integrally comprises a valve body 1, a base 2 and inner hexagon screws 3 (2), wherein the valve body 1 is positioned by surfaces 1-9, surfaces 1-10 and surfaces 1-8 and is fastened on the base 2 by the inner hexagon screws 3; the bottom surface of the base 2 is in flush contact with the bottom surface of the workbench, the included angle between the bottom surface of the base and the bottom surface of the valve body is the complementary angle of the included angle beta between the inclined hole and the bottom surface of the valve body, the two side surfaces of the base 2 are positioned by the vice, and the included angle between the side surface of the base and the side surface of the valve body is equal to the included angle alpha between the surface formed by the central axis of the inclined hole and the normal line of the; the socket head cap screw 3 is used to fasten the valve body 1 to the base 2. The concrete structure is as follows:
in the valve body 1, the whole shape is a cuboid, referring to the direction of FIG. 1, the valve body surface 1-3 is the front surface, the surface 1-8 is the back surface, the surface 1-6 is the upper surface, the surface 1-7 is the lower surface, the surface 1-5 is the left surface, on the basis, the 'ear characteristic' is used for installation, the surface 1-9 and the surface 1-10 are parallel to the surface 1-6, and the surfaces 1-1 and 1-2 are two installation holes;
the valve body 1 contains a multi-dimensional inclined hole 1-4 with the diameter phi d1The included angle between the surface formed by the central axis of the inclined hole and the normal line of the surface 1-6 passing through the center of the circle and the surface 1-5 of the valve body is alpha, and the included angle between the central axis of the hole and the bottom surface 1-6 of the valve body is beta;
in the base 2, the overall shape is a cuboid, referring to the orientation of FIG. 1, a base surface 2-6 is an upper surface, a surface 2-10 is a lower surface, and a surface 2-4 is a right surface, on the basis, a dihedral angle between the surface 2-5 and the base bottom surface 2-4 is alpha, an included angle between the surface 2-9 and the surface 2-10 is pi/2-beta, a middle groove is a valve body installation groove, the groove characteristics correspond to the valve body shape, and the center distance between the base hole 2-1 and the hole 2-2 is equal to the center distance between the valve body hole 1-1 and the hole 1-2.
The installation method comprises the following steps:
in the valve body 1, a valve body surface 1-8 (non-surface 1-3) is in contact positioning with a base surface 2-8, a valve body surface 1-9, a surface 1-10 and a base surface 2-6 are in contact positioning, a hole 1-1 and a hole 1-2 are valve body mounting holes, the two holes are taken as mounting holes in the embodiment, the valve body 1 is fastened on the base 2 through a base threaded hole 2-1 and a base threaded hole 2-2 by using a screw 3, the valve body surface 1-7 is not in contact with the base surface 2-3, and a certain gap exists between the two;
during clamping, the base surface 2-9 is tightly attached to and level with the surface of the workbench, namely is parallel to the xoy surface of the coordinate system of the workbench, the base surface 2-5 and the surface 2-7 are clamped on the workbench through a vice, and the base surface 2-5 and the surface 2-7 are ensured to be parallel to the xoz surface of the coordinate system of the workbench during clamping.
The alignment method comprises the following steps: when the diameter of the boss where the inclined hole is located is phi D, the point which is closest to the valve body surface by 1-8 on the circle is found through electrode touch when the inclined hole is found, the main shaft of the electric spark machine tool moves upwards along the z axis, then moves a distance m in the direction of being close to the circle center along the x direction, and the downward projection of the position is the center of the small hole.
m=d/2+D/2*sinβ (3)
And (5) cutting the tool by an electrode, and processing downwards according to a preset depth to obtain the required inclined hole.